have a 85 streetported 13b 6 port ,holley blue pump /reg and a 650 demon carb,i set floats on carb, car seems fine then maybe 5- 15 minutes later secondarys fuel level raises and drips out gas out of secondary at idle.and when driving causing sputtering?any help would be helpful thanks.

 

You may need to lower the fuel pressure.

 

fuel pressure should be around 6 psi.

 

Interesting... I didn't realize that other carbs besides RB Holleys and Webers are compatible with rotaries. What type of modifications did you need to make? Is there an advantage of running a Demon carb? Not trying to thread jack bro but this is very interesting subject.

 

(hopefully he's premixing)

 

I'm pretty sure you can use any carb for a rotary, the carb is just controlling the air/fuel volume/mixture

You just don't want too big of a carb, or you'd choke the low end.

I wonder if a 650 carb is too big for a sp 13b 6port

 

Possibly, fuel pressure would be an issue too, are you running a fuel pressure regulator?